Solute trapping model incorporating diffusive interface

Abstract Incorporating a diffusive interface that is generally used in phase-field models, a solute trapping model is developed after a so-called solute drag treatment. Adopting a basic approach, defining the free energy density in the interfacial region of phase-field models, a suitable interface shape function is introduced to derive the current model. The equilibrium and non-equilibrium interface behaviours can be described using L (i.e. an important parameter in the present interface shape function). For ke 1, respectively. With increasing interface velocity V, the above inert interface tends to become an adsorptive interface. The above repulsive and adsorptive interfaces are invariable at low V, but, subjected to high V, become a partially adsorptive one and a partially repulsive one, respectively, adjacent to the liquid side. If ke > 1, the equilibrium interface remains inert, solute repulsive and solute adsorptive for −1 ⩽ L ⩽ 1, L > 1 and L